China Science & Technology Forum

[JSCh]

我国首台大型反场箍缩磁约束聚变实验装置建成运行
China's first large scale reversed field pinch magnetic confinement fusion device up and running
发表时间：2015-11-03 16:54来源：新华网
Published: 2015-11-03 16:54 Source: Xinhua​

这是已进入常态化运行的大型反场箍缩磁约束聚变实验装置（11月3日摄）。
Up and running large scale reversed field pinch experimental device (3rd Nov photo).​

近日，我国首台大型反场箍缩磁约束聚变实验装置（KTX，中文简称“科大一环”），在中国科学技术大学完成安装调试并进入常态化运行。据悉，该装置为科技 部“国家磁约束核聚变能发展研究专项”支持的大型装置建设项目，主机总体直径8米，磁场可达7000高斯，等离子体电流达1兆安培，电子温度达600万 度，放电时间达100毫秒。据项目工程总指挥、中科大物理学院刘万东教授介绍，KTX是中国完全自行设计、自主研制集成的国际先进反场箍缩装置。它的建成 将为国内外从事等离子体物理研究的科研人员提供一个全新的大型实验平台，对中国磁约束聚变领域高端人才培养，发展磁约束聚变能科学技术研究事业具有重要意 义。新华社记者刘军喜摄

Translation help by machine:

Recently, China's first large scale reversed field pinch magnetic confinement fusion experimental device (KTX, Chinese referred to as Keda Torus eXperiment), has complete the installation and commissioning by the University of Science and Technology of China. And is now in full operation.

It is reported that the device is supported by MOST(Ministry of Science and Technology)'s national magnetic confinement fusion energy research and development project.

It has a main overall diameter of eight meters, up to 7,000 gauss magnetic field, plasma current up to 1 mega amps, electron temperature of 600 eV, discharge time of 100 milliseconds.

According to the project leader, USTC(University of Science and Technology of China) School of Physics Professor Liu Wandong, KTX is entirely China designed and developed reversed field pinch device. Its completion is essential for providing a new platform for domestic and foreign scientists in conducting large-scale experiments in plasma physics research, for training of China own high-end talent in the field of magnetic confinement fusion, and for the advancement of science and technology of magnetic confinement fusion energy research.

Xinhua News Agency reporters Liu Jun and Xi She

New Chinese nuclear fusion device installed
By Zhang Lulu
China.org.cn, April 10, 2015

Keda Torus eXperiment (KTX), China's first large-scale reversed field pinch (RFP) device, has been installed and been undergoing trials since the end of March, according to media reports.

KTX Design
​

The KTX is used in controllable nuclear fusion that is one of the most cutting-edge technologies in the world. It is complementary to the tokamak and stellarator usually used in nuclear fusion. It is currently under construction in China's University of Science and Technology.

Reports say the device is independently designed and produced by China.

The KTX is six meters high and the diameter of the main body is eight meters, with a total weight of more than 70 tons. It has a major radius of 1.4 m and a minor radius of 0.4 m with an Ohmic discharge current up to 1 MA, according to the website of the University of Science and Technology.

After it goes into full operation, the device will provide scientists with a new platform to carry out plasma research.

China and the United States are the heaviest investors in controllable nuclear fusion. China currently has 16 large-scale nuclear fusion devices, compared to 28 of the U.S.

 

[TaiShang]

China unveils model of first Martian probe

CNTV, November 4, 2015

A model of China's Martian probe will debut at China International Industry Fair, it was announced Monday.

Working staffs install a Mars probe model by China Aerospace Science and Technology Corporation in east China's Shanghai, Nov.2, 2015. The Mars probe model will be exhibited on the 17th China International Industry Fair (CIIF) held from Nov. 3 to 7. [Xinhua]

The 17th China International Industry Fair will open on Tuesday in Shanghai, lasting until Saturday. The golden model, which is a third of its real size, has been given pride of place at China's Aerospace Science and Technology Corp.'s exhibition stand.

Niu Shengda, a satellite expert with the Shanghai Academy of Spaceflight Technology, explained that the probe consists of two parts: an orbiter and a lander.

China's astronomers have set their sights on the Red Planet following a successful soft landing on the moon late last year. They plan to launch the probe in 2020.

"The project is going smoothly," Niu said.

 

[Martian2]

China launches ChinaSat-2C geostationary military communications satellite.

Long March 3B launches with Chinasat-2C | NASASpaceFlight.com

 

[Beast]

China unveils model of first Martian probe

CNTV, November 4, 2015

A model of China's Martian probe will debut at China International Industry Fair, it was announced Monday.

Working staffs install a Mars probe model by China Aerospace Science and Technology Corporation in east China's Shanghai, Nov.2, 2015. The Mars probe model will be exhibited on the 17th China International Industry Fair (CIIF) held from Nov. 3 to 7. [Xinhua]

The 17th China International Industry Fair will open on Tuesday in Shanghai, lasting until Saturday. The golden model, which is a third of its real size, has been given pride of place at China's Aerospace Science and Technology Corp.'s exhibition stand.

Niu Shengda, a satellite expert with the Shanghai Academy of Spaceflight Technology, explained that the probe consists of two parts: an orbiter and a lander.

China's astronomers have set their sights on the Red Planet following a successful soft landing on the moon late last year. They plan to launch the probe in 2020.

"The project is going smoothly," Niu said.

China is smart to do the Mars orbiter and Mars lander at the same time. In these way, we can claim the Asian first bragging right again

 

[cirr]

何梁何利基金2015年度颁奖大会在京举行

中央政府门户网站　中华人民共和国中央人民政府门户网站

2015-11-05 13:46 来源： 科技部网站

11月4日，何梁何利基金2015年度颁奖大会在京举行。最高奖项——“科学与技术成就奖”由解放军信息工程大学邬江兴和海军工程大学马伟明获得。俞茂宏等31名科学家荣获“科学与技术进步奖”，陈占胜等14名科学家荣获“科学与技术创新奖”。

全国政协副主席、科技部部长万钢出席颁奖大会并致辞。何梁何利基金信托委员会主席、评选委员会主任朱丽兰作工作报告。中国药学会理事长、中国工程院院士桑国卫，中国科学院院长白春礼，中国人民解放军副总参谋长乙晓光等出席并为获奖人颁奖。

邬江兴和马伟明带领其团队在各自研究领域成绩斐然，在军用技术向民用转移转化和军民融合协同创新方面业绩突出，最终赢得今年何梁何利奖的最高奖项。今年，除了两位成就奖获得者，国防科技领域另有多项突破性成果值得关注。高级自动寻的飞行器技术研究（hypersonic vehicle）、新型护卫舰总体设计（Type 057 FFG）、新一代舰载战斗机（5th generation carrier-borne stealth fighter）研制等技术成果顺应国家战略需求，为“能打仗、打胜仗”提供了强力技术支撑。

今年获奖人平均年龄为57岁，45岁以下的约占12.8%，获奖人员年龄梯次和结构更加优化。海外归国人员比例达到63.8%。朱丽兰表示，这说明中青年人才和海外归国人员已经成为科技创新的主要力量。其中，一位从台湾地区来到昆山腾达广电科技企业创新创业的领军人物，10年来致力于国内光电产业技术深耕研发，为促进我国TFT-LCD产业长足发展做出重要贡献。（记者 李艳）

何梁何利基金2015年度颁奖大会在京举行_部门新闻_新闻_中国政府网



邬江兴、马伟明获2015年度何梁何利基金“科学与技术成就奖”

2015年11月04日 18:53:30 来源： 新华网

　　新华网北京１１月４日电（记者余晓洁、刘陆）何梁何利基金２０１５年度颁奖大会４日在京举行。全国政协副主席、科技部部长万钢和中国药学会理事长、中国工程院院士桑国卫分别为本年度何梁何利基金最高奖项——“科学与技术成就奖”获得者邬江兴和马伟明颁奖。

　　国家数字交换系统工程技术研究中心教授邬江兴长期从事信息通信网络工程科技研究工作，主持研制成功我国第一台万门数字程控交换机，在信息通讯、宽带网技术、高效能计算机体系结构领域取得了一系列开拓性成果。海军工程大学教授马伟明在舰船新型集成化发电技术（new shipboard integrated power generation technology）、舰船综合电力技术（all-electric ship integrated power system）、电磁发射技术（EMALS）领域破解世界科技难题，推进了我国电磁能武器（electromagnetic energy weapon）装备的跨越式发展。

　　俞茂宏等３１名科学家荣获“科学与技术进步奖”，陈占胜等１４名科学家荣获“科学与技术创新奖”。

　　何梁何利基金由香港爱国金融家何善衡、梁銶琚、何添、利国伟于１９９４年创立，旨在奖励中国杰出科学家，促进祖国科学技术进步与创新。２１年来，何梁何利基金共表彰了１１４７位杰出科技工作者。

邬江兴、马伟明获2015年度何梁何利基金“科学与技术成就奖”-新华网

@Bussard Ramjet

 

[Bussard Ramjet]

何梁何利基金2015年度颁奖大会在京举行

中央政府门户网站　中华人民共和国中央人民政府门户网站

2015-11-05 13:46 来源： 科技部网站

11月4日，何梁何利基金2015年度颁奖大会在京举行。最高奖项——“科学与技术成就奖”由解放军信息工程大学邬江兴和海军工程大学马伟明获得。俞茂宏等31名科学家荣获“科学与技术进步奖”，陈占胜等14名科学家荣获“科学与技术创新奖”。

全国政协副主席、科技部部长万钢出席颁奖大会并致辞。何梁何利基金信托委员会主席、评选委员会主任朱丽兰作工作报告。中国药学会理事长、中国工程院院士桑国卫，中国科学院院长白春礼，中国人民解放军副总参谋长乙晓光等出席并为获奖人颁奖。

邬江兴和马伟明带领其团队在各自研究领域成绩斐然，在军用技术向民用转移转化和军民融合协同创新方面业绩突出，最终赢得今年何梁何利奖的最高奖项。今年，除了两位成就奖获得者，国防科技领域另有多项突破性成果值得关注。高级自动寻的飞行器技术研究（hypersonic vehicle）、新型护卫舰总体设计（Type 057 FFG）、新一代舰载战斗机（5th generation carrier-borne stealth fighter）研制等技术成果顺应国家战略需求，为“能打仗、打胜仗”提供了强力技术支撑。

今年获奖人平均年龄为57岁，45岁以下的约占12.8%，获奖人员年龄梯次和结构更加优化。海外归国人员比例达到63.8%。朱丽兰表示，这说明中青年人才和海外归国人员已经成为科技创新的主要力量。其中，一位从台湾地区来到昆山腾达广电科技企业创新创业的领军人物，10年来致力于国内光电产业技术深耕研发，为促进我国TFT-LCD产业长足发展做出重要贡献。（记者 李艳）

何梁何利基金2015年度颁奖大会在京举行_部门新闻_新闻_中国政府网



邬江兴、马伟明获2015年度何梁何利基金“科学与技术成就奖”

2015年11月04日 18:53:30 来源： 新华网

　　新华网北京１１月４日电（记者余晓洁、刘陆）何梁何利基金２０１５年度颁奖大会４日在京举行。全国政协副主席、科技部部长万钢和中国药学会理事长、中国工程院院士桑国卫分别为本年度何梁何利基金最高奖项——“科学与技术成就奖”获得者邬江兴和马伟明颁奖。

　　国家数字交换系统工程技术研究中心教授邬江兴长期从事信息通信网络工程科技研究工作，主持研制成功我国第一台万门数字程控交换机，在信息通讯、宽带网技术、高效能计算机体系结构领域取得了一系列开拓性成果。海军工程大学教授马伟明在舰船新型集成化发电技术（new shipboard integrated power generation technology）、舰船综合电力技术（all-electric ship integrated power system）、电磁发射技术（EMALS）领域破解世界科技难题，推进了我国电磁能武器（electromagnetic energy weapon）装备的跨越式发展。

　　俞茂宏等３１名科学家荣获“科学与技术进步奖”，陈占胜等１４名科学家荣获“科学与技术创新奖”。

　　何梁何利基金由香港爱国金融家何善衡、梁銶琚、何添、利国伟于１９９４年创立，旨在奖励中国杰出科学家，促进祖国科学技术进步与创新。２１年来，何梁何利基金共表彰了１１４７位杰出科技工作者。

邬江兴、马伟明获2015年度何梁何利基金“科学与技术成就奖”-新华网

@Bussard Ramjet

You tag me.

You know I don't speak Chinese yet.

And you don't even present a brief summary!!!!!!!!!!!!!!!!!!!!!!!!!!

I am boiling over with anger right now!

 

[cirr]

You tag me.

You know I don't speak Chinese yet.

And you don't even present a brief summary!!!!!!!!!!!!!!!!!!!!!!!!!!

I am boiling over with anger right now!

I have highlighted for you the military-related breakthroughs which won 2015 HLHL Foundation achievement awards for progresses in science and technology。

 

[Martian2]

China launches multi-spectral Yaogan 28 satellite.

The Yaogan 28 carries high-resolution electro-optical and infrared sensors (see citation below and the underlined red text).

If you don't already know, I will explain the term "electro-optical."

During the 1960s, the US Corona satellites were purely optical. They recorded images on film and ejected them towards Earth in a "film bucket payload."

Today, the Chinese Yaogan satellite series record the images with a CCD (charge coupled device) sensor. The images are transmitted by encrypted radio to Earth. The CCD is an electronic device. Together with the satellite's optical lenses, you have electro-optical.

China launches Yaogan Weixing-28 via Long March 4B | NASASpaceFlight.com

 

[bobsm]

Chinese team wins breakthrough prize for neutrino research

English.news.cn
2015-11-10 01:04:25

BEIJING, Nov. 9 (Xinhua) -- Chinese scientists have won the 2016 Breakthrough Prize Award in fundamental physics for their research on neutrino oscillation, according to a statement released Monday by an institute with the Chinese Academy of Sciences (CAS).

The Chinese team, Daya Bay Reactor Neutrino Experiment, was led by Wang Yifang, a researcher with the Institute of High Energy Physics under the CAS and professor Kam-Biu Luk with Lawrence Berkeley National Laboratory.

This is the first time Chinese scientists have won the prize, which was awarded at the Ames Research Center of the U.S. National Aeronautics and Space Administration.

In 2012, through the neutrino experiment conducted near the Daya Bay Reactor in Guangdong Province, Chinese and foreign physicists announced that they had confirmed and measured a new type of neutrino oscillation.

The Chinese team will share the prize award equally with another four teams from Japan and Canada.

The award is presented to the five teams for the fundamental discovery and exploration of neutrino oscillations, revealing a new frontier beyond, and possibly far beyond, the standard model of particle physics, according to a statement posted on the prize organization's website.

Neutrinos, the wispy particles that flooded the universe in the earliest moments after the Big Bang, are continually produced in the hearts of stars and and other nuclear reactions.


Chinese team wins breakthrough prize for neutrino research
- Xinhua | English.news.cn

 

[JSCh]

3-D printed ‘building blocks’ of life
4 Nov 2015, Bristol, UK

Scientists have developed a 3-D printing method capable of producing highly uniform ‘blocks’ of embryonic stem cells.

These cells – capable of generating all cell types in the body – could be used as the ‘Lego bricks’ to build tissue constructs, larger structures of tissues, and potentially even micro-organs.

The results are published today, Wednesday 4th November, in the journal Biofabrication.

“It was really exciting to see that we could grow embryoid body in such a controlled manner”, explains Wei Sun, a lead author on the paper. “The grown embryoid body is uniform and homogenous, and serves as a much better starting point for further tissue growth.”

The researchers, based at Tsinghua University, Beijing, China, and Drexel University, Philadelphia, USA, used extrusion-based 3-D printing to produce a grid-like 3-D structure to grow embryoid body that demonstrated cell viability and rapid self-renewal for 7 days while maintaining high pluripotentcy.

“Two other common methods of printing these cells are either two-dimensional (in a petri dish) or via the ‘suspension’ method (where a ‘stalagmite’ of cells is built up by material being dropped via gravity.)” continues Wei Sun. “However, these don’t show the same cell uniformity and homogenous proliferation.”

“I think that we’ve produced a 3-D microenvironment which is much more like that found in vivo for growing embryoid body, which explains the higher levels of cell proliferation.”

The researchers hope that this technique can be developed to produce embryoid body at a high throughput, providing the basic building blocks for other researchers to perform experiments on tissue regeneration and/or for drug screening studies.

“Our next step is to find out more about how we can vary the size of the embryoid body by changing the printing and structural parameters, and how varying the embryoid body size leads to “manufacture” of different cell types” adds Rui Yao, another author on the paper.

“In the longer term, we’d like to produce controlled heterogeneous embryonic bodies” concludes Wei Sun. “This would promote different cell types developing next to each other – which would lead the way for growing micro-organs from scratch within the lab.”

3D-printed building blocks of life - Institute of Physics

 

[cirr]

The world's first 100PFlops supercomputer is coming！

无锡超级计算机中心

无锡恒鼎超级计算中心有限公司成立于2014年7月，是国家超级计算无锡中心的运行主体和服务平台。

国家超级计算无锡中心是以国家高技术研究发展计划（863计划）信息技术领域“高效能计算机及应用服务环境（二期）”重大项目“十亿亿次国产高效能计算机系统”研制成果为基础构建的国家级超级计算中心。该超级计算机全面采用国产处理器和操作系统，具有运算高效和数据安全的行业优势。其系统峰值性能大于100PFlops；系统整机Linpack效率大于等于70%；系统能效比达到5GFlops/W；内存容量大于2.3PB；存储容量20PB。

公司将依托国家超级计算无锡中心为平台，与国内外专家、应用单位等进行密切合作。面向医疗服务、生物医药、海洋科学、现代农业、油气勘探、气候气象、金融分析、信息安全、工业设计、动漫渲染等领域提供计算和技术支持服务，承接国家、省部等重大科技或工程项目，为我国科技创新和经济发展提供平台支撑。

Three hurrys to the SW-5 CPUs。

@Bussard Ramjet

 

[Bussard Ramjet]

The world's first 100PFlops supercomputer is coming！

无锡超级计算机中心

无锡恒鼎超级计算中心有限公司成立于2014年7月，是国家超级计算无锡中心的运行主体和服务平台。

国家超级计算无锡中心是以国家高技术研究发展计划（863计划）信息技术领域“高效能计算机及应用服务环境（二期）”重大项目“十亿亿次国产高效能计算机系统”研制成果为基础构建的国家级超级计算中心。该超级计算机全面采用国产处理器和操作系统，具有运算高效和数据安全的行业优势。其系统峰值性能大于100PFlops；系统整机Linpack效率大于等于70%；系统能效比达到5GFlops/W；内存容量大于2.3PB；存储容量20PB。

公司将依托国家超级计算无锡中心为平台，与国内外专家、应用单位等进行密切合作。面向医疗服务、生物医药、海洋科学、现代农业、油气勘探、气候气象、金融分析、信息安全、工业设计、动漫渲染等领域提供计算和技术支持服务，承接国家、省部等重大科技或工程项目，为我国科技创新和经济发展提供平台支撑。

Three hurrys to the SW-5 CPUs。

@Bussard Ramjet

Great!

When can we expect it to be completed?

 

[cirr]

Great!

When can we expect it to be completed?

It is more or less done。

It was originally scheduled for unveiling to the public during China HPC 2015 11.10 -11.12。

2015年全国高性能计算学术年会: Home

 

[qwerrty]

Chinese team wins breakthrough prize for neutrino research
Nov 10,2015

BEIJING, Nov. 9 (Xinhua) -- Chinese scientists have won the 2016 Breakthrough Prize Award in fundamental physics for their research on neutrino oscillation, according to a statement released Monday by an institute with the Chinese Academy of Sciences (CAS).

The Chinese team, Daya Bay Reactor Neutrino Experiment, was led by Wang Yifang, a researcher with the Institute of High Energy Physics under the CAS and professor Kam-Biu Luk with Lawrence Berkeley National Laboratory.

This is the first time Chinese scientists have won the prize, which was awarded at the Ames Research Center of the U.S. National Aeronautics and Space Administration.

In 2012, through the neutrino experiment conducted near the Daya Bay Reactor in Guangdong Province, Chinese and foreign physicists announced that they had confirmed and measured a new type of neutrino oscillation.

The Chinese team will share the prize award equally with another four teams from Japan and Canada.

The award is presented to the five teams for the fundamental discovery and exploration of neutrino oscillations, revealing a new frontier beyond, and possibly far beyond, the standard model of particle physics, according to a statement posted on the prize organization's website.

Neutrinos, the wispy particles that flooded the universe in the earliest moments after the Big Bang, are continually produced in the hearts of stars and and other nuclear reactions.

http://www.shanghaidaily.com/article/article_xinhua.aspx?id=308602

‘Breakthrough’ science awards total US$22 million
Published: 10 November 2015 3:33 PM

Researchers in physics, mathematics and life sciences were awarded a total of US$22 million (RM96.2 million) in the third Breakthrough Prize Awards funded by key Silicon Valley entrepreneurs.

The prizes aimed at giving glamour and star power to scientific research were awarded at a glitzy event Sunday in Mountain View, California, attended by film stars including Kate Beckinsale, Cameron Diaz and Benedict Cumberbatch.

"By challenging conventional thinking and expanding knowledge over the long term, scientists can solve the biggest problems of our time," said Facebook founder Mark Zuckerberg, one of the backers of the program along with Google co-founder Sergey Brin and Alibaba's Jack Ma.

"The Breakthrough Prize honors achievements in science and math so we can encourage more pioneering research and celebrate scientists as the heroes they truly are."

In life sciences, five prizes of $3 million each were awarded in Sunday's ceremony to Edward Boyden of the Massachusetts Institute of Technology; Karl Deisseroth of Stanford University and Howard Hughes Medical Institute; John Hardy of University College London; Helen Hobbs of University of Texas Southwestern Medical Center and Howard Hughes Medical Institute; and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology.

The life sciences awards recognize advances toward understanding living systems and extending human life, with one prize dedicated to work helping the understanding of Parkinson's disease and neurodegenerative disorders.

In physics, the prizes recognizing advances beyond the standard model of particle physics went to five research teams: the Daya Bay Reactor Neutrino Experiment at University of California, Berkeley and Lawrence Berkeley National Laboratory; the KamLAND Collaboration at Iwate Prefectural University, Japan; K2K and T2K at Japan's High Energy Accelerator Research Organization; the Sudbury Neutrino Observatory at Queen's University, Canada; and the Super-Kamiokande Collaboration at several Japanese universities and research center.

The mathematics prize was awarded to Ian Agol of the University of California at Berkeley and Institute for Advanced Study.

Additional prizes went to junior researchers in physics and mathematics and a new "junior challenge" award was given to Ohio high school student Ryan Chester.

The program was founded by Brin and his former wife Anne Wojcicki; Jack Ma and Cathy Zhang; Russian entrepreneur Yuri Milner and Julia Milner; and Zuckerberg and his wife Priscilla Chan. – AFP, November 10, 2015.

http://www.themalaysianinsider.com/technology/article/breakthrough-science-awards-total-us22-million#sthash.Ttd8uUtX.dpuf

 

[JSCh]

Ultra-thin, tunable, broadband microwave absorber may advance radar cloaking
Chinese scientists have developed an ultra-thin, tunable microwave absorber that can operate over a broad range of frequencies, demonstrating its potential in improving aircraft cloaking, warship stealth and broadband antenna

From the Journal: Journal of Applied Physics

By Zhengzheng Zhang

Washington, D.C., Nov. 10, 2015 – Microwave absorbers are a kind of material that can effectively absorb incident microwave energy to make objects invisible to radar; therefore they are commonly used in aircraft cloaking and warship stealth. Recently, as radar detection devices have been improved to detect the near-meter microwave length regime, scientists are working on high-performance absorbers that can cloak objects in the equivalent ultra-high frequency regime (from 300 megahertz to two gigahertz). However, conventional absorbers for the ultra-high regime are usually thick, heavy or have narrow absorption bandwidth, making them unsuitable for stealth missions.

To solve this problem, a team of researchers from Huazhong University of Science and Technology in China has developed an ultra-thin, tunable broadband microwave absorber for ultra-high frequency applications. This ultra-thin absorbing surface, called an active frequency-selective surface absorber, consists of arrays of patterned conductors loaded with two common types of circuit elements known as resistors and varactors. The unit patterned cell absorbs microwaves and can also be actively controlled by stretching to expand the tunable bandwidth. In a paper published this week in the Journal of Applied Physics, from AIP Publishing, the researchers presented this work.

“Our proposed absorber was fabricated with a stretching transformation pattern, which is both thin and can absorb a wide range of frequencies for near-meter microwave application,” said Wenhua Xu, the primary researcher in the team led by Jianjun Jiang, a professor of School of Optical and Electronic Information at the Huazhong University of Science and Technology, China. “Its absorption range covers a broad band from 0.7 to 1.9 gigahertz below -10 decibel, and the total thickness of the absorber is only 7.8 millimeters, which is one of the thinnest microwave absorbers reported.”

“Usually the thickness of conventional radar absorbers is a quarter the wavelength of the incident microwave. In the high frequency regime, take one gigahertz as an example, the thickness of the absorber would be around 7.5 centimeters, which is too thick and heavy to be used in aircrafts or warships. Our proposed absorber is almost ten times thinner than conventional ones,” Xu said.

Other alternative absorbers, such as metamaterial absorbers made from a resonant metallic structure printed on a dielectric substrate, though significantly thinner than the wavelengths absorbed, have a narrow working bandwidth.

To develop a novel absorber that is both thin and with broadband performance, Jiang’s team employed a type of thin, light periodic structure called a frequency-selective surface, which consists of an assembly of patterned conductors arranged in a two-dimensional array, usually backed by a thin dielectric, to reflect incident microwaves according to their frequency.

In the experiment, Jiang’s team fabricated a broadband active frequency-selective surface with a stretching transformation pattern on a printed circuit board, and soldered the resistors and varactors between each of the two unit patterned cells. The fact that the surface could be stretched meant that the parameters of the unit patterned cell can be actively controlled by stretching.

For the first time, Stretching Transformation is applied to the unit cell pattern to expand the tunable bandwidth. With this technique, it is realizable to be thin and achieve broadband absorption simultaneously.
CREDIT: Intelligent Electronics Institute, Huazhong University of Sci&Tec.

By modeling the absorber using a transmission line, the researchers found that the varactor provides a variable capacitance at varying bias voltage, which produces the device’s tunability, while the lumped resistor with constant resistance reliably produces strong absorption at the resonance frequency. Besides the lumped impedances of the loaded elements, the researchers discovered that the parameters of the unit patterned cells contribute to the device’s absorption performance as well.

“We applied various stretching transformation coefficients to the unit cell pattern to obtain the available parameters to expand the tunable bandwidth,” Xu said. “Our results suggest that a cell pattern with a smaller stretching transformation coefficients ratio (i.e. width to length ratio of the unit cell) leads to higher resonance frequency absorption and produces a wider tunable bandwidth as well.”

Xu noted that it is the first time that stretching transformation pattern is used in the active frequency-selective surface absorber to expand the bandwidth, which turns out to be an effective technique for producing broadband tunability.

“At frequencies below two gigahertz, conventional microwaves absorbers are limited in application by their thickness and narrow absorption bandwidth. Our proposed absorber has achieved broadband tunability and ultra-thin film simultaneously,” Xu said. “The total thickness of 7.8 millimeters is around one twenty-ninth wavelength of the central frequency of incident microwaves, and the ultra-thin absorber with broad bandwidth may be widely used in warship stealth, airplane cloaking and tunable, broadband antennae.”

The researchers’ next step is to study the polarization and the oblique incidence performance for the proposed active frequency-selective surface absorber.

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For More Information:
Jason Socrates Bardi
jbardi@aip.org

240-535-4954

@jasonbardi

Article title:
An ultra-thin broadband active frequency-selective surface absorber for ultrahigh-frequency applications

Authors:
Wenhua Xu, Yun He, Peng Kong, Jialin Li, Haibing Xu, Ling Miao, Shaowei Bie and Jianjun Jiang

Author affiliations:
Huazhong University of Science and Technology

Ultra-thin, tunable, broadband microwave absorber may advance radar cloaking | American Institute of Physics